JPS62205116A - Resin modifier and method for modifying resin - Google Patents

Abstract

PURPOSE:A resin modifier capable of carrying out surface modification such as reduction in coefficient of friction of molded article without damaging resin characteristics, comprising a reaction product of a reactive organic functional group-containing silicone compound and an organic polyisocyanate, containing a free NCO group. CONSTITUTION:A reactive organic functional group-containing silicone compound [e.g., compound shown by formula (n is a value to make molecular weight 980), etc.] is reacted with an organic polyisocyanate (e.g. phenyl isocyanate, etc.) in a functional ratio group wherein the number of NCO group of the latter is preferably 1-2 more than that of the functional group of the former in the presence (or absence) of both an organic solvent and a catalyst preferably at 20-80 deg.C for 10min-3hr to give the aimed modifier containing at least one free NCO groups. The modifier is added to a resin containing hydroxyl group, primary, secondary amino group, amide group, carboxyl group, etc., and used.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a resin modifier, and more particularly, to a resin modifier that can impart excellent surface properties to films, coatings, and other resin molded products. This invention relates to a method for modifying resin.

(Prior art) Conventionally, the surfaces of resin molded products such as various films and coatings have been required to have excellent stain resistance, water resistance, abrasion resistance, and adhesion resistance, and depending on the application, low surface friction has been required. A coefficient is required.

In order to meet such demands, a method has been adopted in which a lubricant such as silicone oil, wax, or fatty acid is added to the resin molded article to impart lubricity, smoothness, and the like.

(Problem to be solved by the invention) According to the method described above, the objective is achieved to a certain extent, but in such a method, the lubricant added to the molded product is deposited on the surface of the molded product over time. Because it bleeds out and causes various problems,
The amount of lubricant added is limited to a few percent at most, and therefore the desired performance cannot be fully exhibited.

As a method to solve the above-mentioned drawbacks, it has been proposed to use a resin with a low coefficient of friction as the resin itself, for example, a polyurethane resin having siloxane bonds in the molecule (for example, JP-A-57-1999-1). No. 176535, 59
-94237, 59-5421, 5g-218
No. 034, No. 58-222436, No. 59-1153
No. 5, Publication No. 59-82636, etc.).

According to such a method, it is possible to form a molded article with a relatively low coefficient of surface friction, but since this polyurethane resin having siloxane bonds contains siloxane bonds in the main chain of the polymer, it is possible to form a molded article with a relatively low coefficient of surface friction. It is difficult to achieve a sufficient reaction, making it difficult to obtain a resin of constant quality, resulting in high costs, and various problems arise due to unreacted silicon compounds. Furthermore, since the polymer is limited to polyurethane resins, there is a problem in that the range of use thereof is significantly limited.

The inventor of the present invention solved the drawbacks of the prior art as described above and as a result of intensive research in order to meet the above demands, the inventor modified the resin using a specific modifier to form molded products such as films and coatings. When doing so, the drawbacks of the prior art as described above are solved, the resin is not limited to polyurethane resins, various resins can be easily used, and molded products with excellent surface properties can be provided. Completed the invention.

(Means for Solving the Problems) That is, the present invention provides (1) a reaction product between a silicone compound having a reactive organic functional group and an organic polyisocyanate, which has at least one free isocyanate group. and (2) a reaction product of a silicone compound having a reactive organic functional group and an organic polyisocyanate, wherein the modifier having at least one free isocyanate group is This is a method for modifying a resin, which is characterized in that it is added to a resin.

To explain the present invention in more detail, the resin modifier that primarily characterizes the present invention is a reaction product of a silicone compound having one reactive organic functional group and an organic polyisocyanate, and the reaction product is It has at least one free isocyanate group in one molecule.

Preferred examples of the silicone compound having a reactive organic functional group used to obtain such a modifier include the following compounds.

(1) Amino-modified silicone oil (s*1Nto, nm2~1O1R-CH3 or Q
C) 13) (msl~l01n=2~1G, R=CH
3 or 0CH3)C)13 ■ H2NC3H8Si [(O9i)nOcH313■ H3 (n 2-10) (Branch point -2-3.R-lower alkyl group.

Is 2~200, tawr 2~200, n
s2~200) (2) Epoxy modified silicone oil (n mist l~200) (m-1~10, n-2~10) (n = 1~200), O[5i(CH3)2011si(C) 13) 3 (branch point -2 to 3, tri-lower alkyl group, 2 to 200 l bottles,
rrr-2-200, n-2-200) CH3 (n-1-10) CH3 (m=1-10, n-2-10) (3) Alcohol-denatured silicone oil (n-1-20
0) (m-1~10. n-2~10) (n-value 0~200) CH3 (+=IN10, ms+10~200,
n-1 to 5) (nml to 200, Rm lower furkyl) (4) Mercapto-modified silicone oil (msl to
10. n-2 to l0) (n-2 to 10) (branch point -2 to 3, R = lower alkyl group, 1 = 2 to 2
00, m-2~200, n-2~200) (
n=1-200, R-lower alkyl group) (5) Carboxyl-modified silicone oil (+5=1-10, nl
I2~1O) (n proverb 1~200) 0[5i(CH3)201nSi(CH3)3 (branch point -2~3, lower alkyl group, 1=2~200,
m-2~200, n-2~200) (n-2~2
Silicone compounds having reactive organic functional groups such as those described above (00, R-lower alkyl group) are preferred examples of silicone compounds in the present invention, and the present invention is not limited to these examples. The exemplified compounds and other silicone compounds are currently in reprint and readily available on the market.

Any of these can be used in the present invention.

The organic polyisocyanate used in the present invention and which is the second characteristic of the present invention is a compound having at least two isocyanate atoms in an aliphatic or aromatic compound, and has traditionally been used as a raw material for the synthesis of polyurethane resins. Widely used.

Any of these known organic polyisocyanates are useful in the present invention. Particularly preferred organic polyisocyanates are as follows.

Toluene-2,4-diisocyanate.

4-Methoxy-1,3-phenylene diisocyanate -
, 4-isopropyl-1,3-phenylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4-butoxy-1,3-phenylene diisocyanate, 2.4-diisocyanate-diphenyl ether, mesitylene diisocyanate, 4.4- Methylene bis(phenylisocyanate), shrylene diisocyanate.

1.5-naphthalene diisocyanate, benzidine diisocyanate, 0-nitrobenzidine diisocyanate, 4.4-dibenzyl diisocyanate, 1.4-tetramethylene diisocyanate, 1.6-tetramethylene diisocyanate, 1.10-decamethylene diisocyanate, 1. 4
- Cyclohexylene diisocyanate, xylylene diisocyanate, 4.4-methylenebis(cyclohexyl isocyanate), 1.5-tetrahydronaphthalene diisocyanate, and adducts of these organic polyisocyanates with other compounds, such as those of the following structural formula: can be mentioned, but
Not limited to these.

0CH3 H3 The resin modifier of the present invention combines a silicone compound having a reactive organic functional group as described above and an organic polyisocyanate as described above, so that the reactive organic functional group and the isocyanate group form an isocyanate group in one molecule. At a functional group ratio of 1 or more, preferably 1 to 2 groups, in the presence or absence of an organic solvent and a catalyst, about 10 It can be easily obtained by reacting in separate dishes for up to 3 hours.

The organic solvent that may be used in the production of such a modifier may be any organic solvent as long as it is inert to each reaction raw material and product. For example, preferred organic solvents include methyl ethyl ketone, methyl -n-
Propyl ketone, methyl isobutyl ketone, diethyl ketone, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, butyl acetate, acetone, cyclohexane, tetrahydrofuran, dioxane, methanol,
Ethanol, isopropyl alcohol, butanol, methyl cellosolve, butyl cellosolve, cellosolve acetate, dimethylformamide, dimethyl sulfoxide,
Pentane, hexane, cyclohexane, heptane, octane, mineral spirits, petroleum ether, gasoline,
Benzene, toluene, xylene, chloroform, tetrachloride! , chlorobenzene, perchlorethylene.

Examples include trichlorethylene.

When the resin modifier of the present invention obtained as described above is produced using an organic solvent, it can be separated from the organic solvent or can be used as a solution of the organic solvent. The modifier of the present invention separated from the organic solvent is generally in the form of a white to brown liquid or solid, and is easily soluble in various organic solvents.

According to various analyzes 1, such as infrared absorption spectrum, elemental analysis, and molecular weight measurement, the modifier of the present invention as described above shows that the isocyanate group of the organic polyisocyanate and the reactive organic functional group of the silicone compound undergo an addition reaction. , for example, when the reactive organic functional group is an ami7 group, -NH
It has become clear that this is a compound in which both are bonded by a CONH bond and has at least one free isocyanate group in each molecule.

According to detailed research conducted by the present inventors, the modifying agent of the present invention contains free isocyanate, so it can be used for various purposes such as hydroxyl groups, primary to secondary amino groups, amide groups, carboxyl groups, etc. It is reactive with resins and is bonded to the main chain of the resin as a side chain rather than the main chain of these resins, so it is possible to make molded products from resin without deteriorating the various properties that resin has naturally. It has been found that when moldings are formed, the surface properties of the moldings are significantly reduced and the surface properties of the molded parts are improved.

Moreover, such an unexpected effect is caused by the fact that the modifier of the present invention
Because it has free isocyanate groups, molded products,
For example, this is because the isocyanate groups also act as a type of modifier that reacts with each other or with the resin before, during, or after the formation of the film.

In the present invention, the resin modified with the resin modifier described above is a variety of conventionally known resins, and any of these can be used. For example, vinyl chloride resin, vinylidene chloride resin, vinyl chloride/vinyl chloride resin, etc. Vinyl acetate/vinyl alcohol copolymer resin, alkyd resin, epoxy resin, acrylonitrile-butadiene resin, polyurethane resin, polyurea resin, nitrocellulose resin, polybutyral resin, polyester resin, silicone resin, Examples include melamine resins, urea resins, acrylic resins, polyamide resins, etc., and particularly preferred are resins having the above-mentioned reactive groups capable of reacting with isocyanate groups in their structures. These resins can be used alone or as a mixture, and can be used as a solution or dispersion in an organic solvent.

Further, the reaction between the resin and the modifier is carried out by reacting at a temperature of about 0 to 150°C, preferably 20 to 80°C, for about 10 minutes to 3 hours in the presence or absence of an organic solvent and a catalyst. It can be done easily.

Molded product 1 For example, to form a film, it is preferable to dissolve or disperse the resin modified with the above-mentioned modifier in the above-mentioned medium and use it in a form such as a paint.Of course, the form of use is not limited to the paint type. For example, in the case of a paint form, the concentration of the resin is preferably about 1 to 50% by weight, and the modifier can be used in a proportion of about 1 to 100 parts by weight per 100 parts by weight of these resins.

The reaction between the modifier and the resin may be carried out at any time 1, for example, during or after the formation of the composition for forming a molded article, during or after the formation of the molded article, or when the resin has an isocyanate group. If the modifiers do not have reactive groups, the modifiers can react with each other, or if water or a polyfunctional compound such as a polyamine is added, the modifier can have a high molecular weight and have the same effect as when using a reactive resin. play.

(Action-Effect) The resin modifier of the present invention as described above is useful for modifying various resins without being limited to specific resins, and depending on the type of resin to be modified, the resin modifier of the present invention can be surface properties of molded articles formed from the resin while retaining various properties such as strength, flexibility, electrical, chemical, and physical properties.

For example, stain resistance, water resistance, abrasion resistance, adhesion resistance, heat resistance, etc. can be significantly improved, and the friction coefficient of molded products can be significantly reduced.

Furthermore, the modifier of the present invention does not become the main chain of the resin, but rather binds to the main chain of the resin and becomes a side chain of the resin, so unlike conventional polyurethane resins containing siloxane bonds. , without reducing the excellent performance of the resin.

In addition, the modifier of the present invention reacts with each other or with the resin in the molded product, has a high molecular weight, and is integrated with the resin.
This solves the drawback that additives bleed onto the surface of the molded product over time, causing various problems. Therefore, it is possible to incorporate a large amount of the modifier into the molded product, and as a result, it is possible to improve the quality of the molded product. Surface properties can be improved.

Next, the present invention will be explained in more detail by giving Examples, Usage Examples, and Comparative Examples. Note that parts and percentages in the text are based on weight.

Example 1 (Production example of modifier) Adduct of 1 mol of trimethylolpropane and 3 mol of tolylene diisocyanate (TDI) (dilonated, Nippon polyurethane acid, N00% 12.5°, solid content 75%)
After stirring 175 parts well at 50° C., 880 parts of terminal amine propyl polydimethylsiloxane (molecular weight 2.200) having the following structure was gradually dropped into the mixture and reacted.

CH3 1; H3 (n is the value that makes the molecular weight 2,200) After the reaction, ethyl acetate is evaporated to form a transparent liquid modifier (Ml
) 976 parts were obtained.

According to the infrared absorption spectrum of this modifier, 2270
The absorption due to the free isocyanate group of /em remained, and an absorption band due to the 5i-0-C group was shown at 1090/cm. Furthermore, when the amount of free isocyanate groups in this modifier was quantified, the theoretical value was 0.83%, whereas the actual value was 0.78%.

Therefore, the main structure of the above modifier is estimated to be the following formula.

8H Shiriichi λ CH3 Example 2 (Production example of modifier) To 196 parts of terminal hydroxypropyl polydimethylsiloxane (molecular weight 980) having the following structure, 24 parts of phenyl isocyanate was added and stirred well at 60°C to react. 213 parts of liquid reaction product (A) were obtained.

(n is the value at which the molecular weight is 980) Next, 52 parts of an adduct of hexamethylene diisocyanate and water (Duranate 24A-100, manufactured by Asahi Kasei, N00% 23.5) was added to 60"O-7' While stirring, 220 parts of the above reaction product (A) was gradually dropped into the mixture and reacted, yielding 263 parts of a colorless and transparent liquid modifier (M2).

According to the infrared absorption spectrum of this modifier, 2270/
The absorption due to free isocyanate groups in cm remains,
It showed an absorption band at 1090/Cm due to the 5i-0-C group. Furthermore, when the free isocyanate groups in this modifier were quantified, the theoretical value was 1.54%, whereas
The actual value was 1.37%.

Therefore, the main structure of the above modifier is estimated to be the following formula.

CO (CH2)8NCO Add 15 parts of n-butyraldehyde, stir well to react at 80°C, and react for 3 hours while removing the generated water from the system under reduced pressure to obtain 238 parts of a transparent liquid reaction product (B). It was done.

(n is the value at which the molecular weight is 1,150) Next, an adduct of 1 mol of trimethylolpropane and 3 mol of xylylene diisocyanate (Takenate DIION, manufactured by Takeda Pharmaceutical, NC 0% 11.5, solid content 75% ) was stirred well at room temperature, and the above reaction product (B
490 parts of ) were gradually added dropwise to the mixture and reacted at 60°C.

After the reaction was completed, ethyl acetate was evaporated to obtain 610 parts of a transparent liquid modifier (M3).

According to the infrared absorption spectrum of this modifier, 2270
The absorption due to free isocyanate groups at /cm remained, and an absorption band due to 5i-oc groups was shown at 1090/cm. Furthermore, when the amount of free isocyanate groups in this modifier was quantified, the theoretical value was 1.34%, whereas the actual value was 1.25%.

Therefore, the main structure of the above modifier is estimated to be the following formula.

Example 4 (Manufacturing Example of Modifier) 2.6-) While stirring 35 parts of lylene diisocyanate and 110 parts of ethyl acetate at 60°C, a terminal mercaptopropyl polydimethylsiloxane having the following structure (molecular weight 1. 580) 316 parts were gradually added dropwise to react.

(1, m, and n are values that give a molecular weight of 1,580) After the reaction was completed, ethyl acetate was evaporated to obtain 340 parts of a transparent liquid modifier (M4).

According to the infrared absorption spectrum of this modifier, 22707
The absorption by free isocyanate groups of cm remains;
It showed an absorption band due to 5i-0-C group at 1090/cm. Furthermore, when quantifying the free isocyanate groups in this modifier, the theoretical value was 2.39%, whereas
The actual value was 2.12%.

Therefore, the main structure of the above modifier is estimated to be the following formula.

(1, m, n are values that give a molecular weight of 1.580) Example 5 (Production example of modifier) 52 parts of hexamethylene diisocyanate and 1 part of ethyl acetate
While stirring well at 60° C., 450 parts of terminal hydroxypropyl polydimethylsiloxane (molecular weight: 2.250) having the structure shown below are gradually added dropwise to 60 parts to react.

(n is the value that gives a molecular weight of 1,580) After the reaction, ethyl acetate is evaporated to form a transparent liquid modifier (M5
) 488 parts were obtained.

According to the infrared absorption spectrum of this modifier, 2270
The absorption due to the free isocyanate group at /cm remained, and an absorption band due to the 5i-0-C group was shown at 1090/cm. Furthermore, when the amount of free isocyanate groups in this modifier was quantified, the theoretical value was 1.67%, whereas the actual value was 1.52%.

Therefore, the main structure of the above modifier is estimated to be the following formula.

Example 6 (Modification of resin) 150 parts of polybutylene adipate having a molecular weight of 2.000 and having a hydroxyl group at the end, 20 parts of 1.3-butylene gellicol
52 parts of tolylene diisocyanate were subjected to an addition reaction in 412 parts of methyl ethyl ketone, and the viscosity was 200 voids/2.
A polyurethane resin solution (solid content 35%) at 0°C was obtained.

Modifier (Ml) was added to 100 parts of this polyurethane resin solution.
5 parts were added and reacted at 80° C. for 3 hours to obtain a modified resin solution (URl) in which the modifying agent and polyurethane resin were combined.

In the resin obtained above, no isocyanate groups were observed by infrared absorption spectrum. This is presumed to be due to graft bonding of the modifier to the resin.

Example 7 (Modification of resin) In place of the modifier (Ml) in Example 6, a modifier (M
A modified resin solution (UR2) was obtained using Example 2) and in the same manner as in Example 6.

Example 8 (Modification of resin) In place of the modifier (Ml) in Example 6, a modifier (M
A modified resin solution (UR3) was obtained using Example 3) in the same manner as in Example 6.

Example 9 (Modification of resin) In place of the modifier (Ml) in Example 6, a modifier (M
A modified resin solution (UR4) was obtained using Example 4) in the same manner as in Example 6.

Example 10 (Modification of resin) In place of the modifier (Ml) in Example 6, a modifier (M
A modified resin solution (UR5) was obtained using Example 5) in the same manner as in Example 6.

Application example 1 Using the five types of resin solutions obtained above, a transparent film was formed by coating and drying on a glass plate so that the dry film thickness was 1 part m, and the static friction When the coefficients and surface conditions were determined, the results shown in Table 1 in F were obtained. In addition, Comparative Example 1 is a case where a resin solution before modification is used, and Comparative Example 2 is a case where 5 parts of silicone oil (SH-200, manufactured by Toshi Silicone Co., Ltd.) is added to a resin solution before modification.

Ichiri g 1 , -1- . - Ho3- URI O,1820 UR20,2100 UR30,1520 UR40,1210 UR50,1360 Comparative example 1 0.632 0 Comparative example 2
0.358
The mark indicates no change, and the mark × indicates that a large amount of silicone oil has bled out from the surface.

As described above, according to the present invention, it is possible to significantly reduce the static friction coefficient of a molded product and maintain a good surface condition.

Example ii (Modification of resin) While stirring 200 parts of acrylic polyol (Hytaloid 3001, manufactured by Hitachi Chemical, solid content 50%), 5 parts of modifier M1 and 5 parts of butyl acetate were added, and the mixture was reacted for 4 hours to transform the modifier. Modified resin solution (ARI
) was obtained.

In the modified resin obtained above, no isocyanate group was observed by infrared absorption spectrum. This is presumed to be due to graft bonding of the modifier to the resin.

Example 12 (Modification of resin) In place of the modifier (Ml) in Example 11, a modifier (
A modified resin solution (AR2) was obtained in the same manner as in Example 11 except that M2) was used.

Example 13 (Modification of resin) In place of the modifier (Ml) in Example 11, a modifier (
A modified resin solution (Al1) was obtained in the same manner as in Example U except that M3) was used.

Example 14 (Modification of resin) In place of the modifier (Ml) in Example 11, a modifier (
A modified resin solution (Al4) was obtained in the same manner as in Example 11 except that M4) was used.

Example 15 (Modification of resin) In place of the modifier (Ml) in Example 11, a modifier (
A modified resin solution (Al1) was obtained in the same manner as in Example 4s11 except that M5) was used.

Application example 2 The above modified resins ARI to AR5 were used and kneaded with a Miki roll in the following formulation to prepare 5 types of paints, and coated on a summer lead phosphate treated steel plate to a dry film thickness of 40 to 45 ILm. A coating film was formed by coating and drying.

Modified resin 63 parts titanium itself
Part 35 Takenate Q-11ON
6. 5 parts toluene
45 parts methyl ethyl ketone 3
0 parts Segosolve acetate 25 parts The stain resistance and surface condition of the coating film obtained above were as shown in Table 2 below. In addition, Comparative Example 1 uses a resin solution before modification, and Comparative Example 2 uses silicone oil (SH-200, manufactured by Toshi Silicone) 5.
This is the case when 50% is added.

(A) (B) ARI OO4,20 AR2003,60 AR3002,20 AR4003,10 AR5003,80 Comparative example work Δ Δ 34.5 Q Comparative example 2
(Not practical as a paint) ×The stain resistance was determined by writing on the paint film with lipstick (A) and oil-based felt-tip pen (B), leaving it at 30°C for 24 hours, and then wiping it off with a cloth. , 0 indicates that no contamination remains, Δ indicates that slight contamination remains, Wear resistance (s + g) is the ASTM wear resistance test, where csio is the wheel and % 50
The value was measured at 1,000 revolutions with a load of 0g applied, and the surface condition was when the film was left for 5 days after being formed. 0 means no change, and × means a large amount of silicone oil bleeds on the surface Indicates that you are out.

As described above, according to the present invention, the stain resistance and abrasion resistance of molded products are significantly improved, and a good surface condition can be maintained.

Usage Example 3 The resin solution URI-UR5 obtained in Example was coated on a polyester film with a thickness of 157 tm using a reverse roll coater so that the dry thickness of each film was 1 lumen, and the solvent The 0th layer was dried to form a heat-resistant layer.
A magnetic layer is formed on the opposite surface according to a conventional method from a dispersion containing Co-containing -Re203 and a binder resin consisting of a normal polyurethane resin and a vinyl chloride copolymer resin,
Five types of magnetic recording media were obtained by cutting each into predetermined widths. The performance of these magnetic recording media was as shown in Table 3 below. Note that Comparative Example 1 is a case where a resin solution before modification was used.

BCDEF Comparative Example 10.52 Yes' Yes Compensation Yes Defective U
R10, 13 None None None None Good U R2
0,20 No No No No Good.

U R30, 23 None None None None Good U R
40,12 None None None None Good U R50,
10 None None None Good, coefficient of friction (A)
is the value (pk) measured between the magnetic layer and the molded article,
Other performances were tested using a videotape, and
The squeal of the tape (B) during the 00th run, the lateral wobbling of the jitter (C), the irregular winding M (D) during fast forwarding of the tape, and the state of wear of the magnetic layer (E) are also observed. The overall evaluation was given as F.

From the above results, it is clear that the magnetic recording medium using the modifier of the present invention has a low friction coefficient of the heat-resistant layer and exhibits excellent running characteristics.

Example 1B (Modification of resin) The modifier obtained in Example 1 ( Add 3 parts of Ml).

The reaction was carried out at 80° C. for 3 hours to obtain a modified resin solution (VRI) in which the modifying agent and the vinyl resin were combined.

In the resin obtained above, no isocyanate groups were observed by infrared absorption spectrum. This is presumed to be due to graft bonding of the modifier to the resin.

Example 17 (Modification of resin) In place of the modifier (Ml) in Example 16, a modifier (
A modified resin solution (VH2) was obtained in the same manner as in Example 16 except that M2) was used.

Example 18 (Modification of resin) In place of the modifier (Ml) in Example 1B, the modifier (
A modified resin solution (VH2) was obtained in the same manner as in Example 16 except that M3) was used.

Example 19 (Modification of resin) In place of the modifier (Ml) in Example 16, a modifier (
A modified resin solution (VH2) was obtained in the same manner as in Example 1B except that M4) was used.

Example 20 (Modification of resin) In place of the modifier (Ml) in Example 16, a modifier (
A modified resin solution (VH2) was obtained in the same manner as in Example IB except that M5) was used.

Usage example 4 100 parts of Co-containing Fe2O3 Any one of the above resin solutions VRI to VR5 (30% solution) 20 parts Polyester type polyurethane resin solution (Rezamin ME12, manufactured by Dainichiseika Industries) 54 parts Dispersant (lecithin)
1 part carbon black
5 parts Nitrocellulose 6 parts Methyl ethyl ketone 270 parts The above ingredients were mixed, kneaded in a ball mill for 50 hours, and further mixed with coronet)
After adding 8 parts of L, mixing was continued for an additional 3 hours, and the kneaded mixture was passed through a filter to obtain a dispersion of five types of magnetic particles.

The five types of dispersions obtained above were applied to a polyester film with a thickness of 15 pm each using a reverse roll coater to a thickness of 5 gm, and after drying the solvent, using a super calendar roll. The surfaces were processed and cut into predetermined widths to obtain magnetic recording media. When the performance of the above magnetic recording medium was investigated, the results shown in Table 4 below were obtained.

Note that Comparative Example 1 is a case where a resin solution before modification was used.

BCDEF Comparative Example 10.28 Minority No No Minority Minority V
R10,15 None None None None flLJ'fV
R20,18 None None None None Good V R3
0,20 None None None None Good VR R40,1
? None None ms Good VR50
, 22 None None None Fi Good The coefficient of friction (A) is the value (gk) measured between the magnetic layer and the support (base film), and the other performance is the value obtained by mounting the film as a videotape. , tape squeal when running 200 times (B), jitter lateral wobbling (C), irregular winding state during fast forwarding of the tape (D), and wear state of the magnetic layer (E)
This is what I observed. The overall evaluation was given as F.

From the above results, it is clear that the magnetic recording medium using the modifier of the present invention has a low coefficient of friction in the magnetic layer and exhibits excellent running characteristics.

Claims (3)

[Claims] (1) A resin modifier, which is a reaction product of a silicone compound having a reactive organic functional group and an organic polyisocyanate, and has at least one free isocyanate group. (2) a reaction product of a silicone compound having a reactive organic functional group and an organic polyisocyanate, which is a modifier having at least one free isocyanate group;
A method for modifying resin, characterized by adding it to resin. (3) The method for modifying a resin according to claim (2), wherein the resin has a group capable of reacting with an isocyanate group.